Taking a solo trip can be a fun and empowering experience, but since you do not have someone to help with driving or any issues that may arise during your trip, it's important to be prepared. Here are a few things to keep in mind when planning a solo road trip:

Ensure your car is in excellent condition.
Before setting out have your car checked to ensure it is running well and you wouldn't have any mechanical issues during your trip. You should also check the condition of your tires and learn how to change them yourself if you don't know how to do so.

Plan entertainment ahead of time. 
A solo road trip means that you wouldn't have another person to control the entertainment so create playlists if you plan to listen to music, find podcasts you would like to listen to or listen to audiobooks.

Only take short haul trips.
Trying to take a long-haul road trip solo isn't a good idea as you might end up driving while tired which can be dangerous. Instead of long trips, focus on going only short distances and if you must do a long-haul trip, break it into a few days so you can drive in the safest conditions and get rest.

Be your own security.
Traveling alone means that you have to be more aware of your surroundings during your trip. Be careful, remain on main roads and do not ever leave your vehicle open and unattended. 

Take advantage of being the sole decision maker.
The best part of taking a solo road trip is that you can make as many stops as you like, visit any places along the way that interest you and create a custom itinerary to your interests. 

Make emergency preparations.
Ensure that your vehicle is fully insured, your driver's license isn't expired, you have a credit card, cash and an emergency roadside membership that can help you if you need it.